Calum Marsh makes a ridiculous generalization:
But it’s important to remember that despite their moralizing, war films are still essentially action films—blockbuster spectacles embellished by the verve and vigor of cutting-edge special effects. They may not strictly glorify. But they almost never discourage.
This is a somewhat strange argument, since it is quite easy to come up with a fairly long list of movies that are explicitly and in some cases deliberately antiwar or at least have the effect of discouraging its audience from supporting most wars. There are the obvious examples, such as Grand Illusion, All Quiet on the Western Front, Apocalypse Now, Gallipoli, and Breaker Morant, and there are also less famous films such as Cold Mountain, Bang Rajan or even the recent propaganda film Five Days of War. Those are just the few that came to mind, and I’m sure that a more complete survey would find many more. Not all of them are good movies, but there are quite a few of them out there. One frequently hears complaints from hawks in the U.S. that filmmakers no longer make enough straightforward pro-war movies as they did in the years following WWII, because there really are relatively fewer war movies that are unabashedly trying to celebrate war than there used to be.
It’s also worth noting that there are two very different kinds of antiwar movies. One kind tries to demonstrate the futility or injustice of a particular war or war in general, while the other engages in an almost cartoonish oversimplification of a conflict in order to portray war as something forced on the good side by an implacable, evil foe. Both want to reject war and condemn it for its horrible effects, but in some of them the responsibility for the conflict is identified (sometimes accurately, sometimes not) as being entirely on one side. I haven’t seen Lone Survivor, but based on what Marsh tells us about the plot it could easily be an antiwar movie that falls into this second category.